Expansion ring for a braided stent

ABSTRACT

A braided stent system includes an expansion ring attached to internal and external surfaces of a lumen. A frame of the ring may impart an outwardly expanding radial force to the lumen, the frame including a plurality of elongate members joined at a coupling and at first and second intersections opposite the coupling. A clip can extend from the intersections and can be operable to slidably secure the frame to the inner and outer surfaces of the lumen.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/246,784, entitled “An expansion ring for a braided stent” and filedAug. 25, 2016, the contents of which are incorporated herein byreference as if set forth verbatim.

FIELD

The present disclosure relates generally to treatment of certain defectsin a vasculature of a patient and more particularly, to expandingbraided stents to a treatment site in a vasculature of a patient.

BACKGROUND

Stents are understood as tubular reinforcements that can be insertedinto a blood vessel to provide an open path within the blood vessel.Stents have been widely used in intravascular angioplasty treatment ofoccluded cardiac arteries, wherein the stent may be inserted after anangioplasty procedure to prevent restenosis of the artery. Stents areoften deployed by use of delivery devices which cause the stent to openwith the objective of reinforcing the artery wall and provide a clearthrough-path in the artery thereby preventing restenosis.

However, the weakness and non-linear nature of the neurovasculaturelimits the applicability of such stents in procedures, for example, inrepairing neurovascular defects. Furthermore, known delivery methods areless useful in vasoocclusive surgery, particularly when tiny vessels,such as those found in the brain, are to be treated. Accordingly, a needexists for a stent that can be used with delivery techniques invasoocclusive treatment of neurovascular defects that provides selectivereinforcement in the vicinity of the neurovascular defect. A need alsoexists for a stent that reduces trauma or risk of rupture to the bloodvessel. It is with respect to these and other considerations that thevarious embodiments described below are presented.

SUMMARY

In some aspects, the present disclosure relates to a braided stentsystem for delivery into a blood vessel is disclosed. They system mayinclude a stent body having a lumen formed by a plurality of braidedmembers with interstices formed therebetween. An expansion ring may bemechanically connected to inner and outer surfaces of the lumen of thestent body and be operable to open the expansion ring and anchor thestent body for receiving a flow diverter. The frame may include a shapememory configuration with a diameter larger than available expansion ofthe stent body.

In an example embodiment, the frame may be operable to impart anoutwardly expanding radial force to the stent body. The frame mayinclude a plurality of elongate members joined at a coupling and atfirst and second intersections opposite the coupling. At least one clipmay extend from the intersections and may be operable to slidably securethe frame to the inner and outer surfaces of the lumen. The clip caninclude a plurality of outer strut members that are aligned and extendedfrom the first intersection and joined at an end opposite the firstintersection. The outer strut members may also be slidable along theinner surface of the lumen. A plurality of center strut members can bedisposed in a gap formed between the outer strut members and also bealigned and extend from the second intersection. The center strutmembers may be slidable along the outer surface of the lumen and can beattached at an end opposite the second intersection in a pore incommunication with the outer strut members.

In an example embodiment, the center strut members can be spaced apredetermined distance from the outer strut members. A laser-cutclipping pattern can be formed between the outer and center strutmembers. The center and outer strut members can also be attached at thepore by being welded, soldered, or glued together. However, the clip isnot so limited and instead the center strut members can be slidablealong the outer surface of the lumen and operable to bias towards thelumen (e.g. inwardly) by a resistance element defined between the centerstrut members and the second intersection. The resistance element couldbe a spring, bias or bowed configuration of the center strut membersand/or the outer strut members to bias towards the lumen to secure theclip with the lumen as desired. Optionally, the plurality of elongatemembers of the frame may be bowed causing the frame to be resistant tocompression. The elongate members may also be twistable a predeterminedamount about the coupling. At least one pair of the plurality ofelongate members can be formed in a V-shape, a U-shape, or an ellipticalcurve.

In other embodiments, the shape memory configuration of the expansionring may include a metal alloy tubing structure such as nickel titaniumthat is laser-cut.

In other example embodiments, the stent body may include a proximal end,a distal end, and a central portion disposed therebetween. The firstexpansion ring can be disposed on or adjacent the distal or proximal endof the stent body with the coupling of the plurality of elongate membersbeing joined at or adjacent the respective distal or proximal end. Asecond expansion ring can also be included that is mechanicallyconnected to inner and outer surfaces of the lumen of the stent body.The second expansion ring can have a frame with a shame memoryconfiguration with a diameter larger than available expansion of thestent body and the second expansion ring may be operable to open andanchor the stent body for receiving a flow diverter. The frame of thesecond expansion ring can similarly include a plurality of elongatemembers joined at a coupling and at first and second intersectionsopposite the coupling. At least one clip can be included in the secondexpansion ring that extends from the intersections and may be operableto slidably secure the frame to the inner and outer surfaces of thelumen.

A method of deploying a braided stent body into a vessel is alsocontemplated. The method includes assembling a plurality of expansionrings with a lumen of the braided stent body, the lumen of the braidedstent body being formed by a plurality of braided members withinterstices formed therebetween and selectively attaching each expansionring with inner and outer surfaces of the lumen of the braided stentbody, each expansion ring imparting an outwardly expanding radial forceto the braided stent body thereby maintaining the lumen of the braidedstent body in an opened position. Each expansion ring can have aplurality of elongate members joined at a coupling and first and secondintersections opposite the coupling; and at least one clip extended fromthe intersections and operable to secure the frame to the inner andouter surfaces of the lumen; slidably attaching a plurality of outerstrut members of the clip to the inner surface of the lumen, each outerstrut member being aligned and extended from the first intersection andjoined at an end opposite the first intersection; and slidably attachinga plurality of center strut members of the clip to the outer surface ofthe lumen, each center strut member being disposed in a gap formedbetween the outer strut members, the center strut members being alignedand extended from the second intersection.

The method may also include attaching the center and outer strut memberstogether at an end opposite the second and first intersections in a porein communication of the strut members; forming the shape memoryconfiguration of each expansion ring with a metal alloy tubingstructure; biasing the center and outer strut members together byincorporating a bias element on or about the first and secondintersections of the clip; spacing the outer and center strut members apredetermined distance; and/or forming an outer access point at a porebetween the outer and center strut members.

Other aspects and features of the present disclosure will becomeapparent to those of ordinary skill in the art, upon reviewing thefollowing detailed description in conjunction with the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale.

FIG. 1 depicts a side plan view of one embodiment of the two of thedisclosed expansion rings assembled at first and second ends of atubular braided stent body.

FIG. 2 depicts a close-up side plan view of one of the rings of FIG. 1assembled at a first end of the tubular braided stent body.

FIG. 3 is a close-up view of plane A-A of FIG. 2 showing certainfeatures of the expansion ring assembled with the tubular braided stentbody.

FIG. 4 is forward plan view of an exemplary expansion ring whenassembled with a tubular braided stent body showing its inner lumen.

FIG. 5 is a schematic overview of one example method of deploying anexemplary braided stent body into a vessel.

DETAILED DESCRIPTION

Although example embodiments of the disclosed technology are explainedin detail herein, it is to be understood that other embodiments arecontemplated. Accordingly, it is not intended that the disclosedtechnology be limited in its scope to the details of construction andarrangement of components set forth in the following description orillustrated in the drawings. The disclosed technology is capable ofother embodiments and of being practiced or carried out in various ways.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. By “comprising”or “containing” or “including” it is meant that at least the namedcompound, element, particle, or method step is present in thecomposition or article or method, but does not exclude the presence ofother compounds, materials, particles, method steps, even if the othersuch compounds, material, particles, method steps have the same functionas what is named.

In describing example embodiments, terminology will be resorted to forthe sake of clarity. It is intended that each term contemplates itsbroadest meaning as understood by those skilled in the art and includesall technical equivalents that operate in a similar manner to accomplisha similar purpose. It is also to be understood that the mention of oneor more steps of a method does not preclude the presence of additionalmethod steps or intervening method steps between those steps expresslyidentified. Steps of a method may be performed in a different order thanthose described herein without departing from the scope of the disclosedtechnology. Similarly, it is also to be understood that the mention ofone or more components in a device or system does not preclude thepresence of additional components or intervening components betweenthose components expressly identified.

As discussed herein, vasculature of a “subject” or “patient” may bevasculature of a human or any animal. It should be appreciated that ananimal may be a variety of any applicable type, including, but notlimited thereto, mammal, veterinarian animal, livestock animal or pettype animal, etc. As an example, the animal may be a laboratory animalspecifically selected to have certain characteristics similar to a human(e.g., rat, dog, pig, monkey, or the like). It should be appreciatedthat the subject may be any applicable human patient, for example.

As discussed herein, “operator” may include a doctor, surgeon, or anyother individual or delivery instrumentation associated with delivery ofa braided stent body to the vasculature of a subject.

It is to be understood that a “self-expanding” stent is a stent whereinthe particular stent fully deploys upon emerging through a deliverydevice such as a sheath, microcatheter, or the like. In this respect,when a self-expanding braided stent emerges, unrestrained outside of therespective delivery device, it should expand and be deployed in thevasculature. However, due to radial forces and friction, braided stentdeployment and recapture following deployment is difficult.

Braided stents may be formed from a plurality of elongate members (e.g.metal wires, polymeric fibers, or strands of material) and these memberscan be very useful in treatment of neurovascular defects. However, whensuch braided members are intended to be self-expanding in a lumen of astent body, known manners of activation of the initially expanding endstruggle to adequately, reliably, and fully open so that the initiallyexpanding end can be used as an anchor point. Moreover, braided stentshave been known to exhibit high internal friction that resists theinherent radial expansion force of the self-expanding braided stent whenbeing deployed to an opened state. Specifically, the relatively highinternal friction can render it difficult to open the initiallyexpanding end of the stent which results in deficiencies in anchoringand deployment. This is particularly true for braided stents deliveredto the desired vessel location through use of a delivery sheath,microcatheter, or the like, since in a closed state (e.g. compressed orcrimped) the stent body typically exhibits friction between the braidedmembers and the delivery sheath or microcatheter.

In practice, braided stents can be delivered to a particular vessel byadvancing a blunt surface against a proximal end of the braided stentcausing the braided stent to axially compress and expand radially. Thisexpansion within the delivery sheath or microcatheter can result in anincreased normal force being applied to the inner surface of thedelivery sheath, microcatheter, or the like thereby also increasingfriction caused by the braided stent.

Expansion rings have been used with braided stents to resolve these andother problem. However, given the size and application, rings that areformed from memory structures (e.g. metal alloy) can be difficult tomanufacture. This is because the respective ring must be placed withinthe inner lumen of the braid so the ring can aid in outwardly expandingthe braid. Attaching the expansion ring inside the braid can bedifficult to the limited access to an attachment zone between the braidand the expansion ring. Specifically, it can be more difficult for anoperator to access the expansion ring from the inner lumen of the braidthan from outside of the braided stent. Such rings may also provide aninner surface with which the bumps on the delivery wire of the braidedstent can engage.

Known solutions to these issues have depended on factors such asmaterial, size, cell design, internal friction, and extra manipulationby the end-user to reliably, quickly and adequately open the braidedstents. In turn, success of the braided stent relied heavily on end-useraccuracy in delivery which unnecessarily increases risk of injury to thepatient. Moreover, such braided, self-expanding stents can be difficultto recapture after being delivered and/or deployed.

One attempt at resolving these problems has included looping a tiny wirethrough the braided stent and the expansion ring of metal alloy and thentying the two components together. This method is not ideal, however,because the tiny wire must be added to the system. If this wire were tobreak off of the implant in the patient, it could also result in anemboli complication.

The herein disclosed expansion ring 1 resolves these and other problemsof the art when assembled with a braided stent body 12 and formingassembly 10. In an example embodiment, assembly 10 permits the operatorto place ring 1 that is constructed with a shape memory structure (e.g.a metal alloy such as nickel titanium [NiTi] (also known as nitinol)within an inner lumen 20 of body 12, while still having an attachmentzone of ring 1 be disposed outside of body 12. Ring 1 may be designed tofacilitate opening and anchoring of body 12 to help the operatoraccurately and easily place a flow diverter. Preferably, ring 1 may belaser cut with a shape memory configuration (e.g. a metal alloy tubingsuch as nitinol) that has a diameter that is larger than the availableexpansion of the braided stent body.

In the following description, references are made to the accompanyingdrawings that form a part hereof and that show, by way of illustration,specific embodiments or examples. In referring to the drawings, likenumerals represent like elements throughout the several figures. Turningto FIGS. 1 and 2, side plan views of the herein disclosed ring 1 andcorresponding body 12 are shown. Body 12 of FIGS. 1 and 2 may be formedfrom a plurality of elongate members 22 braided or otherwise arranged toform a plurality of interstices 24. Members 22 may be formed from two ormore metal wires, or polymeric fibers or strands of material. Ring 1 maybe constructed from one or multiple elongate members 28 and 30interconnected at first 46 and second 36 intersections that togetherform a frame of ring 1 capable of imparting one or more additive radialforces to an inner wall and/or an outer wall of lumen 20 of body 12.Assembling one or more multiple rings 1 with body 12 as shown results ina relatively easy delivery of body 12 within the vasculature that isreliable with reduced risk of injury for the end-user.

In this regard, ring 1 may be selectively positioned and arranged forrapid opening and/or maintaining body 12 in an opened position withouthaving to weld, solder, glue, or otherwise connect ring 1 to body 12itself. Ring 1 can be assembled at a first end 58 of body 12 and ring 1can also be assembled a second, opposite end 56 of body 12. It is to beunderstood that any number of rings 1 can be assembled with body 12including at only one of ends 56 and 58 as well as at any number oflocations between ends 56 and 58 of body 12.

FIG. 2 is a close-up of an exemplary ring 1 of FIG. 1 assembled at end56. As can be seen, assembling ring 1 with body 12 increases anoutwardly extending radial expansion force at end 56 of body 12,opposing end 58, and/or a central portion defined between each end 56and 58. Ring 1 can include one or a plurality support clips 17interconnected with first and second elongate members 28 and 30 thatcollectively cause the ring 1 to fully anchor itself with the lumen 20of body 12. Clip 17 mechanically secures each ring with body 12 by beinginterlaced with the braided, elongate members 22 of body 12 as discussedmore particularly below. Turning to FIG. 3 is a close up view of planeA-A of FIG. 2 more clearly showing clip 17 interlaced with theinterstices 24 and braided, elongate members 22. Preferably, clip 17 ofring 1 may be a “paper clip” type ring with a clip pattern that isformed by a center strut member 32 and an outer strut member 34 into oneend of a metal alloy tube.

As can be previously seen in FIGS. 1-2, first elongate member 28 can bejoined with second elongate member 30 at a second intersection 46.Second intersection 46 may also be attached to body 12 at respectiveends 56, 58, any portion of body 12 therebetween, or may be oriented tobias into or urged against inner lumen 20 of body 12. As can be seen inFIG. 3, each member 28 and 30 is connected to or in communication withclip 17 at intersections 36 and 37, opposite intersection 46.Specifically, strut member 34 extends from members 28 or 30 atrespective intersection 36 while strut member 32 extends from members 28or 30 at respective intersection 37. As can be seen, clip 17 may includetwo aligned members 34 that are elongate and extended away fromrespective first intersection 36 respective end 56 or 58 towards andjoined at connector end 40. Clip 17 may also include two members 32 thatare aligned with each other and relatively smaller in length and/orthickness than members 34, each member 32 being disposed internal to agap formed by members 34 and aligned with members 34. A gap may also beformed between each member 32 through which one or more braided pairs 26of wires 22 can pass. Each member 32 may also be elongate and extendaway from respective intersection 37 towards and joined at connector end40 through one or more welds, soldered connections, chemical adhesive orthe like with the one or more pores 38.

The clip pattern of members 32 and 34 may be laser cut into the metalalloy tube of ring 1. However, ring 1 is not so limited and the clippattern of members 32 and 34 may be formed into one end of the metalalloy tube by any other manufacturing technique as needed or requiredincluding 3-d printing, a CNC machine, a lather, additive manufacturing,etc. Members 32 and 34 together allow the operator to slide ring 1through one or more interstices 24 of the braided stent body 12 in amanner similar to sliding a paper-clip over a piece of paper. In thisrespect, members 32 may slidably inserted over and/or external to wires22 of body 12 whereas members 34 may slidably inserted inside of wires22 of body 12. Members 32 and 34 may then be welded, soldered, glued, orotherwise connected together inside one or more pores 38, or open spaceof body 12 to secure ring 1 to body 12. For example, FIGS. 2-3 depictthe herein discussed body 12 assembled with ring 1 at a first end 56 inan example embodiment. Member 34 also provides a solid, stable surfaceoperable to aid in the delivery of system 10 when crimped down into body12 such as a microcatheter. Alternatively, members 32 and 34 may bebiased or otherwise operable to be urged against each other with aresistance element of intersection 37 (e.g. a spring or bowedconfiguration) so that members 32 and 34 naturally pivot towards eachother. In this embodiment, members 32 and 34 may or may not be connectedat pore 38. Member 32 may be heat treated so that it can be raised apredetermined distance above the outer strut member 34. In this respect,the raised member 32 may allow the operator to more easily place members32 and 34 through interstices 24 during assembly as there would be moreseparation between the clip and the braided stent wires.

As can be seen, while members 28 and 30 are seen integrally formed witheach other in FIGS. 1-4 at intersections 36, 37, and 46, ring 1 is notso limited and members 28 and 30 may be removably attached to each otherthrough a fastener including a band, bolt, clamp, coupling, dowel, hook,latch, key, or the like. Members 28 and 30 may also be adhered to eachother or welded to form one or more of intersections 36, 37, and 46.Additionally, if one or more fasteners is used in a particularimplementation, the fastener can be removably connected or welded,soldered, and/or crimped thereon. Fasteners and/or members 28 and 30 canbe formed of a radiopaque metal, such as platinum or tantalum, or may beformed of a non-radiopaque material, such as stainless steel.

By adding clip 17 to ring 1, each ring 1 is allowed to interlace withbody 12 and operatively attach to both the inner and outer portions ofbody 12 without a permanent or rigid attachment to body 12 itself bywelding, soldering or through a chemical adhesive. Once members 32 and34 are effectively assembled with body 12, braided members 22 can alsomove independently from ring 1 which removes the adverse impact that apermanent or rigid attachment could otherwise have on body 12 to expandwhen assembled with an expansion ring. Intersection 46 may also includea rotatable and/or twistable coupling so that ring 1 is capable offlexing a predetermined amount when body 12 and ring 1 is in use.

FIG. 4 is a forward plan view of an exemplary ring 1 when assembled withbody 12 showing each of clips 17 and corresponding intersections 46 withregards to lumen 20 of body 12 in the uncompressed state. The hereindisclosed ring 1 could be used with any number of clips 17 as needed orrequired depending on need or preference. It is to be understood thatring 1 can be a compression element capable of flexing a predeterminedamount. In this respect, ring 1 could move between a compressedconfiguration before deployment within the vasculature as well as adeployed configuration with a lumen 20 having a greater diameter thanthe compressed configuration. Elongate members 28 and/or 30 may alsoinclude a curved or arched portion that bows with a predeterminedresistance to compression. It is to be understood that each pair ofmembers 28 and 30 in ring 1 may have the same or a different resistanceso that ring 1 can be individualized for the specific vasculatureimplementation. Additionally, members 28 and 30 ring 1 may be formed asa V-shape as shown in FIGS. 1-3 with acute and/or oblique angles.However, ring 1 is not so limited and instead of being V-shaped, members28 and 30 can be formed as “U” shaped, elliptical shaped, generallycurved, loop or bight at the junction portion.

The herein disclosed ring 1 and corresponding system aids inmanufacturing an easy and safe to use braided stent by utilizing anouter access point formed at pore 38 between members 32 and 34 as wellas utilizing a connection along the inner surface of body 12 via members34 and corresponding members 28 and 30.

Ring 1 and its constituent features may be formed of a superelasticmaterial, such as Nitinol, or may be formed of a non-superelasticmaterial, such as spring steel or MP35N, an alloy of 35% nickel, 35%cobalt, 20% chromium, and 10% molybdenum, by weight. Members 28 and 30of each ring 1 may also be formed from a shape memory material having ashape memory position in the opened state.

Turning to FIG. 5, a method 100 of deploying one or more of any of theherein disclosed rings 1 with lumen 20 of body 20. The method 100 caninclude steps 110 through 140. Step 110 may include assembling one ormore rings 1 with lumen 20 of body 20. Step 120 may include selectivelyattaching each ring 1 with inner and outer surfaces of lumen 20 so thateach ring 1 may impart an outwardly expanding radial force to body 12thereby maintaining lumen 20 in an opened position. Step 130 may includeslidably attaching outer members 34 of clip 17 to the inner surface oflumen 20, each outer strut member 34 being aligned and extended from thefirst intersection 36 and joined at an end opposite the firstintersection (e.g. pore(s) 38). Step 140 may include slidably members 32of clip 17 to the outer surface of lumen 20, each member 32 beingdisposed in gap 5 formed between members 34, members 32 being alignedand extended from the second intersection 37.

Others steps may be included in method 100 such as attaching members 32and 34 together at an end opposite intersections 36,37 in one or morepores 38, crimping the members 34 into the outer surface of lumen 20,forming the shape memory configuration of each ring 1 with a metal alloytubing structure, biasing members 32, 34 together by incorporating abias element on or about intersections 36, 37 of clip 17, spacingmembers 32, 34 a predetermined distance apart, and/or forming an outeraccess point at one or more pores 38 between members 32, 34.

The specific configurations, choice of materials and the size and shapeof various elements can be varied according to particular designspecifications or constraints requiring a system or method constructedaccording to the principles of the disclosed technology. Such changesare intended to be embraced within the scope of the disclosedtechnology. The presently disclosed embodiments, therefore, areconsidered in all respects to be illustrative and not restrictive. Itwill therefore be apparent from the foregoing that while particularforms of the disclosure have been illustrated and described, variousmodifications can be made without departing from the spirit and scope ofthe disclosure and all changes that come within the meaning and range ofequivalents thereof are intended to be embraced therein.

What is claimed is:
 1. A braided stent system comprising: a stent bodyhaving a lumen formed by a plurality of braided members with intersticesformed therebetween; an expansion ring mechanically connected to innerand outer surfaces of the lumen of the stent body, the expansion ringhaving a frame with a shame memory configuration with a diameter largerthan available expansion of the stent body, the frame imparting anoutwardly expanding radial force to the stent body, the frame comprisinga plurality of elongate members joined at a coupling and at first andsecond intersections opposite the coupling; and at least one clipextended from the intersections and operable to slidably secure theframe to the inner and outer surfaces of the lumen; wherein theexpansion ring is operable to open and anchor the stent body forreceiving a flow diverter.
 2. The system of claim 1, wherein the clipcomprises: a plurality of outer strut members aligned and extended fromthe first intersection and joined at an end opposite the firstintersection, the outer strut members being slidable along the innersurface of the lumen; and a plurality of center strut members disposedin a gap formed between the outer strut members, the center strutmembers being aligned and extended from the second intersection; whereinthe center strut members are slidable along the outer surface of thelumen and attached at an end opposite the second intersection in a porein communication with the outer strut members.
 3. The system of claim 2,wherein a laser-cut clipping pattern is formed between the outer andcenter strut members.
 4. The system of claim 2, wherein the center strutmembers are spaced a predetermined distance from the outer strutmembers.
 5. The system of claim 2, wherein the center and outer strutmembers are attached at the pore by being welded, soldered, or glued. 6.The system of claim 1, wherein the clip comprises: a plurality of outerstrut members aligned and extended from the first intersection andjoined at an end opposite the first intersection; and a plurality ofcenter strut members disposed in a gap formed between the outer strutmembers, the center strut members being aligned and extended from thesecond intersection; wherein the center strut members are slidable alongthe outer surface of the lumen and operable to bias inward by aresistance element defined between the center strut members and thesecond intersection.
 7. The system of claim 1, wherein the shape memoryconfiguration of the expansion ring comprise a metal alloy tubingstructure.
 8. The system of claim 7, wherein the metal alloy is nickeltitanium and the structure is laser-cut.
 9. The system of claim 7,wherein the shape memory configuration is formed from a shape memorymaterial having a shape memory position in an opened state.
 10. Thesystem of claim 1, wherein the plurality of elongate members of theframe are bowed causing the frame to be resistant to compression, theelongate members being twistable a predetermined amount about thecoupling.
 11. The system of claim 10, wherein at least one pair of theplurality of elongate members is formed in a V-shape, a U-shape, or anelliptical curve.
 12. The system of claim 1, wherein the stent bodyincludes a proximal end, a distal end, and a central portion disposedtherebetween; and wherein the first expansion ring is disposed on oradjacent the distal or proximal end of the stent body with the couplingof the plurality of elongate members being joined at or adjacent therespective distal or proximal end.
 13. The system of claim 12, furthercomprising: a second expansion ring mechanically connected to inner andouter surfaces of the lumen of the stent body, the second expansion ringhaving a frame with a shame memory configuration with a diameter largerthan available expansion of the stent body, wherein the second expansionring is operable to open and anchor the stent body for receiving a flowdiverter; the frame comprising a plurality of elongate members joined ata coupling and at first and second intersections opposite the coupling;and at least one clip extended from the intersections and operable toslidably secure the frame to the inner and outer surfaces of the lumen.14. A method of deploying a braided stent body into a vessel, the methodcomprising: assembling a plurality of expansion rings with a lumen ofthe braided stent body, the lumen of the braided stent body being formedby a plurality of braided members with interstices formed therebetween;selectively attaching each expansion ring with inner and outer surfacesof the lumen of the braided stent body, each expansion ring imparting anoutwardly expanding radial force to the braided stent body therebymaintaining the lumen of the braided stent body in an opened position,each expansion ring comprising: a plurality of elongate members joinedat a coupling and at first and second intersections opposite thecoupling; and at least one clip extended from the intersections andoperable to secure the frame to the inner and outer surfaces of thelumen; slidably attaching a plurality of outer strut members of the clipto the inner surface of the lumen, each outer strut member being alignedand extended from the first intersection and joined at an end oppositethe first intersection; and slidably attaching a plurality of centerstrut members of the clip to the outer surface of the lumen, each centerstrut member being disposed in a gap formed between the outer strutmembers, the center strut members being aligned and extended from thesecond intersection.
 15. The method of claim 14, further comprising:attaching the center and outer strut members together at an end oppositethe second and first intersections in a pore in communication of thestrut members.
 16. The method of claim 14, further comprising: formingthe shape memory configuration of each expansion ring with a metal alloytubing structure.
 17. The method of claim 14, further comprising:biasing the center and outer strut members together by incorporating abias element on or about the first and second intersections of the clip.18. The method of claim 14, further comprising: spacing apart the outerand center strut members a predetermined distance.
 19. The method ofclaim 14, further comprising: forming an outer access point at a porebetween the outer and center strut members.